<div class="card">
    <div class="card-header">
        <button class="btn btn-block text-left" data-toggle="collapse"
            data-target="#accordion{$i}">{$field.title}</button>
    </div>
    <div id="accordion{$i}" class="collapse multi-collapse">
        <div class="card-body">{$field.content}</div>
    </div>
</div>